Toxicokinetic Effects of Micro/Nano Plastics on Human Health

Plastic, due to its diverse properties, finds applications in various fields such as agriculture, packaging, pharmaceuticals, textiles, and construction, to name just a few. However, excessive use of plastic leads to the accumulation of a large amount of plastic waste, and improper management of this waste results in serious environmental problems. During the COVID-19 pandemic, plastic production reached unprecedented levels. It is estimated that by 2024, around 70 million tons of plastic will end up in nature due to the imbalance between the volumes of plastic consumed and the capabilities for managing plastic at the end of its life cycle. A comprehensive understanding of environmental pollution should include not only the assessment of the amount of plastic in landfills but also the more dangerous degradation products, such as micro- and nanoplastics (MNPs) in the hydrosphere, biosphere, lithosphere, and atmosphere. Microplastics (MPs) are plastic particles ranging in size from 1 µm to 5 mm, while nanoplastics (NPs) are particles up to 100 nm in size. MNPs pose a greater threat to the environment than their larger counterparts. Due to their small size and potential toxicity to humans, MNPs are of particular concern. Epidemiological studies indicate that disorders such as lung nodules, asthma, and blood clots may be caused or exacerbated by exposure to MNPs. Although direct evidence of MNPs' impact on human health remains limited, research is needed to assess the health risks posed by MNPs. This chapter discusses issues related to toxicokinetics, mechanisms of toxicity, and methods for detecting MNPs in the human body. Nevertheless, the potential of environmentally derived MNPs to harm human health remains insufficiently studied, and further research is needed to fill the existing knowledge gaps in this area and to develop more effective strategies for the safe management of MNPs.